By Louis Cordony, 21 Jun 2017Reviews

You can nab a seriously good luxury performance car for circa $100K these days.

There’s a reason why Bruce Willis fills your television screen every Christmas. People love Die Hard because it’s about someone regular-looking proving much more than that.

Cars are no different. If something unassuming pulls up beside a Ferrari and then suddenly blows off into the distance, it’s like seeing Jackie Chan walk into a bar and kick a boozed-up giant out cold. You’d feel equally bemused and delighted.

Such things are better known as sleepers. We love them. And when coughing up for a luxury sedan priced nigh-on six-figures, with performance and covert looks thrown in, it’s obvious the Northern Hemisphere does too.

Our four contenders all hail from Europe, each sporting six-cylinders and 3.0 litres of force-fed grunt. But while they might sound similar on paper, the differences in their executive-friendly suits already set them apart.

First up is Audi. The original 100 S4, its first S-badged model, looked less suited to full-berry-giving than it did Uber Black duties (if such a thing existed in the early ’90s), but it’s shaped all its hot four-doors since.

The just-landed B8 S4 is $30K more expensive than the next A4 variant, but singling it out from its cheaper brethren isn’t easy. The A4 already oozes menace with its sharp lines, gleaming grille, and furrowed daytime running lights, so you’d have to zoom in on the S4’s front brakes, in all their six-piston glory, to pick it.

But the Audi may as well advertise its pedigree with neon signs when compared to our test’s bargain entry, the $89,900 BMW 340i. Sure, its crease lines, shark-nose, and squinty headlights keep its six-year-old looks fresh, but seen here in Luxury Line trim, that ‘40i’ badge and dual-rear pipes are the only real nod to its stonk.

This won’t be easily fixed either with something like an M Sport package. The pack only changes the wheels, grille colour, guard badges, and front bumper. Until BMW offers a factory M Performance variant, this meekly dressed 340i wins this test’s trainspotter prize.

AMG C43 hasn’t been so shy. It’s been two decades since a ‘43’ has graced a Mercedes-Benz C-Class’s backside in Oz. But Benz has rebadged the once Euro-only C450 AMG Sport as just that.

And while those figures no longer correlate to engine size, they hint at the fact that this car punches harder than its formal facade suggests.

Engineered by Mercedes-AMG, the C43’s ‘AMG’ calipers and drilled front brake discs allude to its performance and help justify its $101,900 ask, without options, while those big eyes, rounded surfaces, and sparkling grille, plugged into its unique front bumper, make it the softest on the eyes here.

However, the Germans aren’t the only masters of disguise. Britain, after all, is James Bond’s homeland and Jaguar’s long been in the sleeper game. The Jaguar XE is the successor to the forgettable X-Type, and the car’s aluminium sheet metal doesn’t look out of place.

Dropped on optional 20-inch wheels it looks positively sexy, though it also brings with it a long options list that takes its $105,350 base price to an eye-watering $125,270, only four grand of which it wears on its exterior.

What truly defines its ‘S’ badge, however, is the brawny V6 lurking under its long, drooping hood. It’s borrowed from the Jaguar F-Type and is the only engine that’s picked the supercharging route, its twin-screw blower helping spin up 250kW and 450Nm.

These cars might be separated only by three cubic centimetres, but it’s the Jaguar’s that feels largest in capacity at the drag strip. Rolling the Jaguar from the line is the best way to manage rear grip and allow its blower to build boost with revs.

It sets off wailing like its sports car cousin and whining like a supercharged drag car, needing 5.28sec to reach the 100km/h mark before breaking the 400m ribbon in 13.45sec.

Our test’s other rear-driver, the BMW, prefers a bit of a smoke. It’s the only car with an actual launch control system (found in iDrive), but it rarely maintains a set stall rpm and walking it from rest results in waiting for the turbo to wind up.

However, with luck, and wheelspin, it’ll charge to 100km/h in 5.51sec, before finishing the quarter mile a tenth behind the Jaguar at 13.57sec.

Plugged with BMW’s all-new B58 unit, it makes 240kW/450Nm, but it spins the highest and hits the heaviest. Plasma-coated bores and a closed-deck block were used to strengthen the new engine, while shorter turbo paths cut lag.

So the needle happily sails past its indicated redline to a 7250rpm cut-out in manual mode, and its torque peak is spread over the widest area from 1380rpm to 5000rpm.

Mercedes-AMG’s 3.0-litre twin-turbo V6 in the C-Class, contrastingly, goes about this stuff more frenetically. Its 270kW and 520Nm outputs arrive in what feels like rapid gunfire from its nine-speed automatic. It’s geared so short it needs to upshift twice before 80km/h.

You’d think this would hurt its acceleration times, but the numbers don’t lie. There’s no Race Start system, so launching it requires switching off ESP, dialling up 2550rpm with a firm two-step, and then lifting before its all-paw drive system digs in.

As it slingshots forward a metallic howl rips from its optional performance exhaust in Sport Plus mode, punctuated by an abrupt crack on every shift before its 6300rpm cut-out. Triple figures arrive in 4.61sec, 400m passes in 12.87sec.

Switching from the AMG to the S4 is like swapping an assault rifle for a shotgun. Thrust arrives via its ZF-made eight-speed auto’s ratios in thick, linear slugs.

This is partly because Audi’s filled the V6’s valley with a twin-scroll turbocharger, which required flipping around the heads so the exhaust valves point inwards, helping it push 260kW/500Nm through its four tyres.

Launch control’s a simple two-step affair like it is in the Merc, the only difference being its quattro drivetrain tenses up with a higher stall at 3100rpm. But it’s still just as aggressive. With each upshift the ZF ’box buries little jabs into your back and the all-alloy V6 blurts out a beefier note, and bassy ignition-cut farts, as it flings the S4 to 100km/h in 4.74sec and 400m in 12.99sec.

No prizes for guessing that our all-paw duo ravage the rear-drivers from a standing start. However, roll-on tests flip the pecking order on its head.

The BMW will tear free of the pack from 80-120km/h in third gear, relying on longer gearing and lighter weight to cut it in 3.1sec. That’s a tenth faster than both the Audi and Jaguar, while extremely short gearing lets the AMG down, forcing it to nab fourth at 114km/h and register a 3.2sec sprint.

Run the same test in sixth gear and the Merc leapfrogs back into first place, its muscly outputs helping it zap the 40km/h gap in 5.9sec. But the BMW’s thick torque spread means it’s breathing down its neck the whole way as it does the same in 6.0sec. Meanwhile, the Audi and Jaguar need 6.6sec and 7.7sec respectively in terms of the sixth-gear sprint.

However, the 340i reels ’em in so quickly at the speed traps it makes you wonder if the petrol station at BMW’s engine dyno facility only stocks 95 RON.

It flies across the quarter mile finish line at 175.56km/h, while the Merc trails with 174.03km/h, the Audi 173.69km/h, and the Jaguar 172.08km/h.

Break free for the twisty stuff and you’ll discover the 340i’s six also dominates the car’s driving experience. The higher the revs, the sweeter it sounds and harder it pulls.

It’s only a shame its suspension doesn’t extend the enjoyment into the bends. Even with low-profile Bridgestones and adaptive M suspension, the 340i fails to tell you what’s happening at a surface level.

There’s little feedback from its tiller on how much purchase the front tyres have. It also feels like the front strut set-up can’t translate available grip into sharp turn-in, so the stability police show up well before the fun’s even started, yapping at wheels to keep it within the road lines.

It’ll have you scanning the options list for a fix, but the 340i’s adaptive suspension is already pinched from the M Sport package; and the optional M brakes, at $1400 for the set, are the only chassis upgrade.

They won’t be enough to save the 340i from its dynamic woes, but are worth it, as you’ll sail past a few apexes adjusting to the stock set’s underwhelming power.

Switching to the Jaguar feels like shedding a pair of mitts. At first, though, it’s hard to trust for a few reasons. The Jaguar XE’s brakes are by far the most powerful here, which goes to show there’s nothing wrong with sliding calipers; and also, the steering feel numbs when you get stuck in.

Then on the way out of corners the LSD-by-brake system sporadically nabs at the rear axle, and as a result, your confidence falls significantly, too.

Once you find smooth tarmac, though, you can finally let the XE S sink in its claws. The electric steering is sharp, fluid, and commands a front-end that feels magnetised to apexes. It’s here that its firm suspension setup pays off, as you can start to ratchet up the commitment and uncover its huge levels of lateral grip.

But the Jaguar’s ferocious demeanour lingers over rough stuff. Those 20s pick up small bumps and while there’s more travel in its dual-mode adjustable dampers than the BMW’s, they work harder to keep its mass in check. It’ll fidget after big dips, too.

Once again, though, the grippier pair prove themselves in another class. The Audi S4 rides so well you’d think Heathcote’s back roads snaked their way through Audi’s test grounds. With multi-links and adaptive dampers all around, it swallows big bumps and high-frequency stuff with pillow-like compliance.

Even around town, with 35-profile tyres, you’re not afraid to line-up speed humps or potholes.

Admittedly, the Audi’s not the most natural corner-carver against the Jaguar or Merc. The first quarter of steering lock feels out at sea and the nose is a bit pushy, but across a twisting road the optional ($2950) electronically controlled hydraulic diff is so good, it feels like Audi stole the technology from VW’s abandoned WRC operation.

Instructions on how to drive it would sound right at home in an infomercial – ‘floor the gas, and watch it magically tighten your line’.

Just don’t try the same stuff in the AMG. Its all-wheel drive system doesn’t have a limited-slip differential at all and shoots 67 per cent of its grunt rearwards. Coupled with its hefty outputs, the traction-control light flickers like a bug zapper if you sink the right-foot as early as you do in the Audi. That said, once straightened, its all-wheel grip allows it explode out of corners.

The Merc’s hard-charging character isn’t smoothed out by its adaptive dampers. It feels like its suspension bushes were pinched from a race car. Harsh ridges are absorbed with a huge thud, and the dampers have so much travel in Comfort mode the car sails over them like its air-suspended.

Switching to its Sport Plus mode cuts out the damper float, and the upside is the C43 feels so tied down you suspect AMG pinched the Merc C63 S’s suspension system.

There’s an extremely direct front-end connected to a crisp-feeling steering rack. It’s positive, and so rich with feedback that any yaw movements are thwarted with almost telepathic dabs of opposite lock.

And if you’re going to annihilate apexes there’s no better place to sit than in the Merc. The optional Performance seats grab your kidneys tighter than an organ thief, while the raked seating position drops you low into the car.

The baby S-Class design theme inside is a classy touch, only tainted by the COMAND system’s confusing menu structure. Mind you, the seats, wheel, and exhaust come as part of a $4990 Performance Package.

Our four are each fantastic for cruising in lavishly cloaked performance, and long shall their kind reign. But if value is your guiding principle, the BMW’s a stand-out pick. Short of autonomous driving tech, it boasts the same kit, badge prestige, and refinement as the Audi or AMG for less cash.

The interior also doesn’t seem ‘that’ old, and it’s a sharp looker from the outside. However, its flat seats speak loudest about its undercooked dynamic talent. The 340i’s all about that silken, turbine-like engine, and ignores what the balanced chassis underneath it could be.

One glimmer of hope comes from the $10K discount over its rivals, which could be used toward an M Performance Accessories LSD. Maybe along with a non-variable steering rack (optional) this would have made this a fairer fight for the BMW. However, until the new 3 Series arrives in 2019, this one’s under-braked, out-gripped, and over-powered.

On the other hand, Jaguar’s XE S injects more handling and grip into the sleeper sedan mix. Meanwhile, a blend of razor-sharp turn-in, dramatic engine noise, and handsome looks mean it has a charisma other brands might need multiple generations to craft.

But while it’s dazzling enough to negate the $15K price gap between it and the BMW, it’s nowhere near fast enough, refined, or well equipped to justify its hike over the other two. Maybe the MY18 model, which scores the F-Type S’s 280kW engine, can reignite its chances at toppling the German duo’s establishment.

When it comes to grunt and drama, however, the C43’s the undisputed king. There’s so much to love about its drivetrain, its gearbox works well when left to its own devices, and it could decimate all if only injected with a proper limited-slip diff.

As a stepping stone between Mercedes-Benz’s C-Class range and AMG’s lunatic asylum, it’s a perfect fit. But crucial ride and power-down issues sink its chances at clenching the top spot.

This brings us to the S4, which has emerged as an exceptional all-rounder from this test. Not only does it basically match the Mercedes for straight-line speed, it’s genuinely magic when the road twists and turns.

Yes, the differential is optional, but even without it, the S4’s clever quattro system and thumping drivetrain are strong weapons in its arsenal – the noise also shows it still knows how to have fun. And once you’re done terrorising tarmac, its delightful ride and smart interior bewitch you into its driver’s seat for the drive home.

Audi deserves credit for sneaking it under the $100K mark considering the scroll-length list of standard kit. And the autonomous driving tech would raise eyebrows at Tesla, too.

The S4’s fast, reasonably priced, technologically advanced, and matches this all to subtle good looks. Forget Bruce Willis, the S4 slides onto scene like Superman. Wearing glasses and a smart, business savvy suit, but brandishing otherworldly powers that need to be driven to be believed.